Thursday, November 17, 2005

Eating dairy DOESN’T facilitate weightloss

I’ve been wanting to blog about this for months, but this is the first chance I’ve had. I am so sick of these ads that assert that eating three servings of dairy products a day helps you lose weight or, even more far-fetched, that drinking 24 ounces of milk in 24 hours will help you lose more weight than cutting calories alone. From the September 2005 Nutrition Action Health Letter (this post draws from that article, which I recommend):

Only three small published studies have found greater weight loss in people who were told to cut calories and eat dairy foods, and all were done by one researcher with a patent on the claim.

The government’s expert nutrition advisory panel has called the evidence on dairy and weight loss “inconclusive.”

Two new studies have found that dairy foods don’t help people lose weight.

Michael Zemel is the University of Tennessee nutrition researcher who, in the 1990’s, was investigating what happens when men with high blood pressure increase their calcium by eating more dairy foods. Zemel found that after the men ate two cups of yogurt a day, their blood pressures fell and they lost an average of 11 pounds of body fat. In 2000 he did three studies that put overweight people on a calorie-restricted diet for a period of time. A third of them had a regular calorie-restricted diet, a third of them had a regular calorie-restricted diet plus calcium supplements and a third had a calorie-restricted diet that included three servings of dairy products a day.

In each study, the people on the diet that included three servings of dairy a day lost more weight than the other two groups, and in 2002 Michael Zemel and his wife filed for a patent on the claim that calcium or dairy products can prevent or treat obesity. In 2004 Zemel also published a book “The Calcium Key” (“the revolutionary diet discovery that will help you lose weight faster”).

So far, that all might seem persuasive. Why doesn’t Zemel’s claim about calcium and weightloss hold up to scrutiny?

For one thing because Zemel’s published studies only used a total of 46 people. Janet King of the University of California at Berkeley, who chaired the federal government’s Dietary Guidelines Advisory Committee says, “All of our recommendations in the Dietary Guidelines report were based on multiple randomized controlled trials of hundreds of individuals. The work on milk and weightloss was very limited by comparison.”

Other things Zemel clarifies in the Nutrition Action article that aren’t mentioned in any of the dairy ads:

1) His work is specific to people who aren’t already consuming enough calcium, but when asked how much is “enough” Zemel says, “My honest answer is I don’t know exactly.”

2) His work is specific to people who are overweight and he would not expect dairy consumption to affect the body weight of people who aren’t overweight.

3) Whey and curds are the active components of dairy products. Yogurt and milk were the key dairy products in Zemel’s studies because they contain whey. Cheese doesn’t contain whey or curds (so anyone who’s eating cheese and thinking they’re helping their diet is in fantasyland).

The dairy industry conveniently leaves all this information out of its ads and wants us to believe that we can chomp down on cheese and ice cream every day while losing pounds and inches, or while staying thin. Why else would they feature women like Bebe Newirth and Lindsay Lohan in their “Got Milk?” ads?

So, let’s all take a look at the dairy-and-weightloss advertising for what it is: a slick campaign designed to rake in more profits for the American dairy industry which feels neglected by a population that would rather suck down soft drinks than milk and that increasingly sees cheese as a high-calorie source of saturated fat. More recent studies that have investigated Zemel’s claims have found that eating milk, cheese and yogurt does not burn more fat or cause weight loss. In anybody. And the “drink 24 ounces of milk every 24 hours” was completely cooked up by the dairy industry and isn’t supported by a single study, not even Zemel’s.

So there.

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